Frijns was leading Sunday's international GT endurance event on Mount Panorama from seven-time Supercars champion Jamie Whincup (Mercedes) when the race was declared with 20 minutes remaining on the clock.

He had been in fuel saving mode, like most of the front runners, and admitted he didn't think they'd have finished had the race continued under normal conditions.

"I was pushing but also trying to save as much fuel as I could," said Frijns after celebrating with Audi Sport Team WRT co-drivers Stuart Leonard (Britain) and Dries Vanthoor (Belgium).

"I don't think we could have made it without a safety car.

"We are really happy, we didn't expect it from the start when we had issues all the way through. But from halfway to the end everything went fluently."

The pivotal moment came when former Supercars driver Ash Walsh got tied up with a backmarker and crashed into the wall at the top of the mountain, leaving him helpless with his car sideways across track.

A horror collision. Pic: Seven

Kiwi Johnny Reid, in a Mercedes GT, came over the hill at full pace and slammed into the side rear of the Audi, his attempted evasive action preventing what could have been a far more serious accident.

Officials decided there was not enough time to clean up the substantial debris and complete the race under green flags.

It was Audi's third win at the event and first since 2012.

Whincup finished second in the Mercedes AMG with teammates Kenny Habul, Tristian Vautier and Raffaele Marciello while Tim Pappas, Jeroen Bleekemolen, Luca Stolz and Marc Lieb were third in a Porsche 911 GT3.

Like Frijns, Whincup had no complaints about the race, which was strewn with crashes and safety car appearances, being declared early.

"We couldn't be happier, we certainly maximised," Whincup said. "I am a big believer that the team who does the best job should win and these guys (Audi) did an awesome job.

"We were tight on fuel as well, but hey what's Bathurst without a fuel race? We were hanging in there. We wouldn't have made it to the end but we got lucky."

The race opened up when three of the then top five - Steven Kane in a Bentley (third), Kevin Estre in a Porsche 911 (fourth) and Chaz Mostert in the BMW M6 - tangled with backmarkers at Forrest's Elbow, taking all three out of the race.

Mostert, who had started from pole position and dominated the early parts of the race, appeared to cause the melee through frustration at being stuck in the traffic.

Earlier, New Zealand driver Andrew Bagnall was transferred to hospital after a big smash at the top of the mountain where he was rear-ended.

The 70-year-old Bagnall, competing in the Pro-Am class, sustained several broken ribs on his right side and a broken right pelvis.